App freezes at critical parts of the game

The game is fun and addictive but It gets only three stars from me because

1.) In an Arena match the app occasionally freezes on the screen where youre given a choice to watch an ad to get another bird. Even toggling to the home screen then back to the game doesnt unfreeze the app. Ive lost Arena matches and game levels because of this bug.

2.) I dont like the fact that the coin amount required to get more birds to continue a level or arena match increases from 60 coins then to 120 coins. I didnt even try a third time. You work hard to earn the coins and can use them up in no time flat.

3.) The Arena match also freezes when you try to use your gems to extend the match. I lost a match because the game froze. Please fix the bug so players can pick up where they left off when the program freezes in the Arena match.

hachuck about Angry Birds 2, v2.15.1